The B+W 72mm IR Infracolor (099) Filter is mainly used in conjunction with color infrared films to block portions of short-wave radiation (blue and blue-green) up to 520nm. It reaches full transmission of radiation around 600nm, which it retains beyond the feasible sensitivity range of false-color films. By blocking the blue range with these films you are able to capture a better range of colors with more differentiation between tones. This filter still allows you to depict vegetation and plants in a unique reddish manner due to the infrared reflectivity of chlorophyll. The filter factor is highly variable depending on the sensitivity of your specific film and the lighting situation under which you are photographing in.
B+W filters are constructed from high quality Schott glass for increased optical clarity and color fidelity. They feature a brass filter ring for durability as well as jamming prevention.